I have created a d20 Ability Calculator for Android (http://www.heikkitoivonen.net/android/d20abicalc/). If you use a point buy system similar to the Dungeons & Dragons 3.5e DMG p. 169, you can configure the points for your campaign and use your Android-powered mobile device to come up with the optimal ability scores for your character with just a few taps of the screen. Easy to use, no network required, help files included (although I doubt you'll need them). Sells for $0.99 USD.

Not for D&D 4e!

If you have any ideas on how to improve the program, please let me know!

The Dead of Winter campaign was played with custom 3rd edition Dungeons & Dragons rules and custom world. The campaign has since ended, but the massive world description, house rules, character descriptions and 38 chapter journal of the adventure as it took place is available for your reading pleasure.